Driveshaft won't fit

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mshred

mshred

The Green Manalishi
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I had my 727 out for the winter to do a quick inspection, and install a manual valvebody. Everything went back together as it came apart. I have also installed a 9.5" aftermarket converter. Converter was installed, fully seated, before mating transmission back to the engine and reinstalling in the car.

I don't recall the driveshaft being tight to come out, but upon trying to reinstall it today, with the yoke bottomed out in the trans, I can not get the u joint into the diff. The front of the car is jacked up, and the rear wheels on the ground. Something is off, and im not sure what. Should I try installing with the rear wheels off the ground as well? Seems to me that would make it even more difficult/shorten the distance. Maybe rotate the yoke on the diff and try reinstalling that way? Im stumped and annoyed, as Im really hoping this doesnt mean I need to pull the trans...
 
Red x on post 2.
Maybe the engine shifted back enough to cause the issue.
Try jacking the rear higher than front, stands under axle.
Did you put in a new rear seal and it`s a little longer than old?
 
mopar head said:
Red x on post 2.
Maybe the engine shifted back enough to cause the issue.
Try jacking the rear higher than front, stands under axle.
Did you put in a new rear seal and it`s a little longer than old?
Click to expand...
Seal was not changed.
On my Scamp I installed the driveshaft many times with front jacked up and rear wheels on the ground, so this stumped me and concerned me.
The car is on a hill (rear of car is downhill) so maybe if I do jack it up level, maybe that helps.
I was always under the impression that rear axle hanging made the distance shorter?
 
Did any **** get into the yoke causing it not to go in all the way? A mouse put seeds in there? Seriously, I've seen it all.
 
CFD244 said:
Did any **** get into the yoke causing it not to go in all the way? A mouse put seeds in there? Seriously, I've seen it all.
Click to expand...
I cleaned it and blew it out with compressed air, but I'll check again
 
It should go in on the ground. If it don't make 1/2 inch shim plates for the front of the front spring hangers. This will also give quarter clearance for tires and better shackle angle for springs to work if the are straight up and down., Also got 29x14.5's on the back doing this.
 
Did you have any trouble installing the rear mount. If yes,
check your rear mount to be sure it's in the factory position.
If no, I'm out.
unless the slip yoke is bottoming on the output shaft which, for some reason, has been pushed to the rear, like what happens when one of the clutches is not properly engaged on a planetary ........................
but, I can't see this as a thing if only the VB was changed.
 
And now things are getting worse- now, no matter what gear I put the trans into, I can not sping the output shaft at all, either direction...
 
mshred said:
And now things are getting worse- now, no matter what gear I put the trans into, I can not sping the output shaft at all, either direction...
Click to expand...
This probably has something to do with the parking brake rod when you installed the VB. It has to be oriented correctly
 
Is your car folding up in the middle? lol.
mshred said:
And now things are getting worse- now, no matter what gear I put the trans into, I can not sping the output shaft at all, either direction...
Click to expand...
Yeah that speaks to the forward clutch possibly being bound up; easy mistake to make but should have been caught when checking the Endplays, after the front was installed.
But what do I know, I'm just a lawnmower mechanic.
 
CFD244 said:
This probably has something to do with the parking brake rod when you installed the VB. It has to be oriented correctly
Click to expand...
99% sure it was installed correctly as I checked for smooth operation before bolting on the pan...but I can drop the pan and check again in the car
AJ/FormS said:
Is your car folding up in the middle? lol.

Yeah that speaks to the forward clutch possibly being bound up; easy mistake to make but should have been caught when checking the Endplays, after the front was installed.
But what do I know, I'm just a lawnmower mechanic.
Click to expand...
When you say bound up, what exactly do you mean? The trans worked fine when pulled, I inspected the clutches and bands, and re assembled along with the new vb. I could swear that I tried turning the output shaft on the bench going through the gears, but it was so long ago now im secons guessing with this issue that has presented itself...

It can't be converter related?
 
IIRC, the park rod has to go through a spring loaded dog in there. When the trans is shifted into park, the lock is activated and you are in park. In any other gear, the lock is deactivated, and the car is not in park. Just spit balling, but since the valve body was the only thing that you messed with, maybe that rod position is keeping it in park.......Just a suggestion.
 
CFD244 said:
IIRC, the park rod has to go through a spring loaded dog in there. When the trans is shifted into park, the lock is activated and you are in park. In any other gear, the lock is deactivated, and the car is not in park. Just spit balling, but since the valve body was the only thing that you messed with, maybe that rod position is keeping it in park.......Just a suggestion.
Click to expand...
Definitely possible. I guess I can pull the pan and try removing the park rod completely and see what happens before I yank the entire trans out
 
Again, IIRC, I think you'll feel a click when the rod slips into position when you installed the valve body. It has to overcome the spring pressure of the tapered part shown in the file photo from the net......But it's been a while. Good luck.

1721269348893.jpeg
 
It will take IDK maybe five times as much power to, by hand, rotated the trans output shaft in the reverse direction, than in the forward direction; this is normal.

I cannot, in my mind's eye, see how the park rod can be installed wrong.
mshred said:
When you say bound up, what exactly do you mean? The trans worked fine when pulled, I inspected the clutches and bands, and re assembled along with the new vb. I could swear that I tried turning the output shaft on the bench going through the gears, but it was so long ago now im secons guessing with this issue that has presented itself...

It can't be converter related?
Click to expand...
You say that you inspected the clutches and the bands, then reassembled.
I'm assuming this means you took the entire front end out of the trans, cuz IDK how else an inspection can be performed.
if the gear train stayed in the back of the trans, then it's endplay has not changed.
Thus if the too-long fault is inside the trans , Most of the time it's because the rear clutch was not fully engaged on all 4 or 5 clutch plates. So then, when the pump goes in, and you snug the bolts down, you just bend the last clutch which then drives the front end-play to zero, or less. I have lost count of how many times I have seen it.
The endplay spec for the rear is not much, so even if the front is jammed into the rear, normally, this does not or should not affect you driveshaft installation.
But it sureaschit will affect the manual rotation of the output shaft. As will too tight bands rubbing on the drums.
IDK how the backend can be assembled too-long and the snapring still be properly installed. Excessive end-play sure, but not pushing the output shaft back.
As for the convertor affecting the driveshaft, I cannot make that connection.
I could sooner imagine that something got between the bellhouse and the engine, during the mating.
BTW, when you went to bolt the TC to the crank, you had to pull the TC forward out of the trans some quarter inch or more, to where the flex-plate was ............ right?
 
AJ/FormS said:
It will take IDK maybe five times as much power to, by hand, rotated the trans output shaft in the reverse direction, than in the forward direction; this is normal.

I cannot, in my mind's eye, see how the park rod can be installed wrong.

You say that you inspected the clutches and the bands, then reassembled.
I'm assuming this means you took the entire front end out of the trans, cuz IDK how else an inspection can be performed.
if the gear train stayed in the back of the trans, then it's endplay has not changed.
Thus if the too-long fault is inside the trans , Most of the time it's because the rear clutch was not fully engaged on all 4 or 5 clutch plates. So then, when the pump goes in, and you snug the bolts down, you just bend the last clutch which then drives the front end-play to zero, or less. I have lost count of how many times I have seen it.
The endplay spec for the rear is not much, so even if the front is jammed into the rear, normally, this does not or should not affect you driveshaft installation.
But it sureaschit will affect the manual rotation of the output shaft. As will too tight bands rubbing on the drums.
IDK how the backend can be assembled too-long and the snapring still be properly installed. Excessive end-play sure, but not pushing the output shaft back.
As for the convertor affecting the driveshaft, I cannot make that connection.
I could sooner imagine that something got between the bellhouse and the engine, during the mating.
BTW, when you went to bolt the TC to the crank, you had to pull the TC forward out of the trans some quarter inch or more, to where the flex-plate was ............ right?
Click to expand...
Trans came apart to inspect clutches in both drums and band material. Was reinstalled exactly how it came out. I triple checked clutches lined up, and it felt like it all sat back down properly into the sunshell at the right depth. At this point I think I am better off just pulling it and seeing whats happening on the bench, as shitty as it is...

And yes, converter had to be pulled out a bit to bolt up to the flexplate.
 
mshred said:
Seal was not changed.
On my Scamp I installed the driveshaft many times with front jacked up and rear wheels on the ground, so this stumped me and concerned me.
The car is on a hill (rear of car is downhill) so maybe if I do jack it up level, maybe that helps.
I was always under the impression that rear axle hanging made the distance shorter?
Click to expand...

Draw a triangle with a 90 degree corner and get back to me on which side is the longest : D

Sorry you are having trouble. Should have went with a G Force 101a : /
 
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